Disclosed herein is a vehicle seat and a method for manufacturing the same, and particularly, a vehicle seat and a method for manufacturing the same capable of suppressing an increase in size.
In general, a vehicle seat is configured to be capable of displacing a seat surface position thereof.
For example, in consideration of the physiques of occupants being individually different, a lot of vehicle seats are known to include a height adjustment mechanism to be able to adjust the height of the vehicle seat depending on the physique of the occupant with the aim of improving drivability or the like in a driver seat and ensuring comfort or the like in other seats.
As these height adjustment mechanisms, link mechanisms are often adopted.
That is to say, in a seat cushion frame becoming a frame of the seat surface of the vehicle seat, the frame of the right and left direction is formed by arranging a pair of side frames on the right and left thereof.
Then, the link mechanisms are structured by using link members or the like to both the right and left side frames, and by connecting the links on the both sides by way of connecting members at the rear side and the front side of the vehicle, the link mechanisms on the both right and left sides are interlocked.
In this manner, by interlocking the both right and left side frames, the seat cushion frame is moved up and down.
When such mechanisms (the link mechanisms) are structured and the vehicle seat (the seat cushion frame) is moved up and down, the structured link mechanisms has to be connected to the both right and left side frames as described above.
That is to say, the need to connect the link members arranged on the both right and left side frames by the connecting members arises.
Therefore, a method for connecting these connecting members to the link members arranged on the both right and left side frames is proposed (for example, see Patent Registration No. 3497923 B (“the '923 Document”).
In the technique described in the '923 Document, a seat lifter is disclosed.
The seat lifter moves a seat frame up and down by way of the link mechanisms.
One end portion of a lifter shaft connecting the right and left sides of the seat frame is connected to a sector gear constituting the link mechanism.
On the lifter shaft formed by a pipe, an enlarged diameter portion is formed at a predetermined position by bulging, and after pressing the sector gear into the lifter shaft from the end portion thereof, both are joined by welding at the enlarged diameter portion side.
However, if it is thus configured by forming a hole in a link mechanism constituting member and pressing the end portion of the shaft into the hole (that is, by passing the end portion of the shaft through the link mechanism constituting member and fixing it thereto), the end portion of the connecting member (the shaft) projects to the opposite side.
As thus described, if the end portion of the connecting member (the shaft) projects to the opposite side, the end portion was likely to obstruct the arrangement of other constituting members.
Moreover, a projecting portion, a component for avoiding interference between a projection portion and other members, and a device itself are increased in size.
Further, in a case where link connecting members are arranged on the side frames constituting a seating frame (the seat frame), the end portion of the shaft hinders the arrangement, so that a configuration for absorbing the projecting portion is required.
For example, there were needs of forming projection holes or of forming concave portions for putting the end portion of the connecting member (the shaft) therein, in the side frames, but this increased cost and man-hours.
Therefore, the development of a mounting structure of a connecting member (a shaft) for avoiding interference of side frames and members around the side frames and avoiding an increase in the size of a device, and the development of a vehicle seat with the same were strongly desired.